bugfix in trans buffer

Author: mag1c-h

ucm/store/cache/cc/trans_buffer.cc

@@ -355,8 +355,7 @@ TransBuffer::Handle TransBuffer::Get(const Detail::BlockId& blockId, size_t shar
         strategy_->BucketUnlock(iBucket);
         return Handle{this, iNode, owner};
     }
-    iNode = Alloc(blockId, shardIdx);
-    MoveTo(iBucket, iNode);
+    iNode = Alloc(blockId, shardIdx, iBucket);
     strategy_->BucketUnlock(iBucket);
     return Handle(this, iNode, true);
 }
@@ -381,7 +380,7 @@ size_t TransBuffer::FindAt(size_t iBucket, const Detail::BlockId& blockId, size_
     return iNode;
 }
 
-size_t TransBuffer::Alloc(const Detail::BlockId& blockId, size_t shardIdx)
+size_t TransBuffer::Alloc(const Detail::BlockId& blockId, size_t shardIdx, size_t iBucket)
 {
     for (;;) {
         auto iNode = strategy_->FetchNode();
@@ -395,10 +394,14 @@ size_t TransBuffer::Alloc(const Detail::BlockId& blockId, size_t shardIdx)
         meta->block = blockId;
         meta->shard = shardIdx;
         meta->ready = false;
-        if (meta->hash != invalidIndex) {
-            strategy_->BucketLock(meta->hash);
-            Remove(iNode);
-            strategy_->BucketUnlock(meta->hash);
+        const auto oldBucket = meta->hash;
+        if (oldBucket != iBucket) {
+            if (oldBucket != invalidIndex) {
+                strategy_->BucketLock(oldBucket);
+                Remove(oldBucket, iNode);
+                strategy_->BucketUnlock(oldBucket);
+            }
+            MoveTo(iBucket, iNode);
         }
         strategy_->NodeUnlock(iNode);
         return iNode;
@@ -417,10 +420,11 @@ void TransBuffer::MoveTo(size_t iBucket, size_t iNode)
         next->prev = iNode;
         strategy_->NodeUnlock(n);
     }
+    meta->hash = iBucket;
     head = iNode;
 }
 
-void TransBuffer::Remove(size_t iNode)
+void TransBuffer::Remove(size_t iBucket, size_t iNode)
 {
     auto meta = strategy_->MetaAt(iNode);
     auto p = meta->prev;
@@ -437,7 +441,9 @@ void TransBuffer::Remove(size_t iNode)
         next->prev = meta->prev;
         strategy_->NodeUnlock(n);
     }
+    if (strategy_->FirstAt(iBucket) == iNode) { strategy_->FirstAt(iBucket) = n; }
     meta->prev = meta->next = invalidIndex;
+    meta->hash = invalidIndex;
 }
 
 void* TransBuffer::DataAt(Index pos) { return strategy_->DataAt(pos); }

ucm/store/cache/cc/trans_buffer.h

@@ -102,9 +102,9 @@ class TransBuffer {
 
 private:
     size_t FindAt(size_t iBucket, const Detail::BlockId& blockId, size_t shardIdx, bool& owner);
-    size_t Alloc(const Detail::BlockId& blockId, size_t shardIdx);
+    size_t Alloc(const Detail::BlockId& blockId, size_t shardIdx, size_t iBucket);
     void MoveTo(size_t iBucket, size_t iNode);
-    void Remove(size_t iNode);
+    void Remove(size_t iBucket, size_t iNode);
     void* DataAt(Index pos);
     void Acquire(Index pos);
     void Release(Index pos);